It did not took off because the whole sales pitch was utter nonsense. Why would anyone put 3rd party 5G BTS inside their buildings and then pay for data, when they can use WiFi for free + they control the network so they can decide how data are shared between stations and which stations are allowed to be logged in.
I can see that 6G is pitching... exactly same thing. Which predictably is going to fail... on exactly same issue.